Lucidity GC-FID Does Cocaine, Again!

Last week I set out to test the myth that there was cocaine on US currency, specifically dollar bills.  After testing several dollar bills, I came up empty handed on any of the bills testing positive for cocaine, other than the bill that I purposely spiked with cocaine.  Speaking with colleagues, I learned that I should have tested higher denominations.  So, I went and collected a $100 and three $20’s from my coworkers.  At first they were skeptical about giving me the money, but I assured them, they did know where I worked and would get their money back, eventually.  

These new bills were soaked in methanol as before for 24 hours with some agitation.  Then, the methanol was concentrated down in the fume hood in an evaporating dish.  Once concentrated, I brought the volume back to 5 mL, then I took an aliquot to inject into the Lucidity GC-FID and my results were surprising.  

To obtain the chromatograms, I used my standard Drugs of Abuse method that I used last week.

I was told that when other chemists had tested money for cocaine, it was the $100’s that tested positive the most often, so I started there and crossed my fingers.  As the chromatogram was being produced, I watched in anticipation, hoping that I would see something.

Figure 1. Zoomed in chromatogram of a $100 bill showing a methadone peak but no cocaine

Unfortunately, as before, there isn’t a peak at 36 minutes and 38 seconds, so no cocaine on the Benjamin, but there was an interesting peak at 34:06 that I decided to investigate later in the study.

Next, I tested the three $20 bills.  Again, I waited patiently for that elusive cocaine peak to show.  And to my surprise, at the appropriate retention time there seemed to be a very small peak.  I waited for the method to finish and checked the results.  The peak was so small that I had to manually integrate the peak, and it was barely above the noise level of the GC-FID, but it was there.

Figure 2. $20 bill with a small cocaine peak, and a methadone peak

This shows that the myth it true, there is cocaine on US currency! I figured after testing the $1 bills and then a $100 and a $20 bill that I wouldn’t be able to confirm the myth, but on the first $20 bill I got a positive result for cocaine.  As the next two chromatograms were being produced I continued to watch, but the next two wouldn’t have the same success as the first.

To show that the peak isn’t just me wanting to see something that really wasn’t there, I overlaid the three $20 chromatograms.

Figure 4. Overlay of $20 chromatograms showing a cocaine peak labeled 2, only appearing on the red chromatogram

The cocaine peak in the red chromatogram is very small but comparing it to the other chromatograms shows that the peak does exist.  There is in fact cocaine on money!  Middle school me would be so excited to know that it was true and there was proof in my hands.

Now, if you look at all of the chromatograms, every single one of them shows a peak at 34 minutes and 6 seconds.  Earlier when I was running the cocaine standards, I had another drug of abuse standard, methadone, and the retention time was very similar to these mystery peaks on all of the bills.

Figure 5. Methadone chromatogram

I cannot confirm 100% that the peaks on the money is in fact methadone without further investigation, but I would say that there is a very likely chance that there is methadone on money.  To be confident that I have found methadone I would need to use a GC/MS to get the mass spectra of methadone and compare it to my peak of interest, stay tuned for that.

The really interesting part of this study to me was that while I set out to find cocaine on money, and after testing ten different bills and three different values, I did find one bill with cocaine on it, but I also found other drugs that I wasn’t even looking for.  This is why I truly love science, I was looking for one thing and working toward that, and I found something that was equally as interesting that I wasn’t looking for or even considered.